The pH of blood stream is maintained by aproper balance of H_(2)CO_(3) and NaHCO_(3) concentrations. What volume of 5 M NaHCO_(3) solution should be mixed with a 10 ml sample of blood which is 2 M in H_(2)CO_(3) in order to maintain a pH of 7.4 ? K_(a) for H_(2)CO_(3) in blood is 7.8xx10^(-7).

The pH of blood stream is maintained by aproper balance of H_(2)CO_(3)

1.	The pH of blood stream is maintained by aproper balance of H_(2)CO_(3) and NaHCO_(3) concentrations. What volume of 5 M NaHCO_(3) solution should be mixed with a 10 ml sample of blood which is 2 M in H_(2)CO_(3) in order to maintain a pH of 7.4 ? K_(a) for H_(2)CO_(3) in blood is 7.8xx10^(-7).
Answer» Solution :`pH = pK_(a) + LOG. (["Salt"])/(["Acid"])` `7.4= - log. (7.8xx10^(-7)) + log. ([NaHCO_(3)])/([H_(2)CO_(3)])` `log .([NaHCO_(3)])/([H_(2)CO_(3)])=7.4+ (-7+0.8921)=1.2921 or ([NaHCO_(3)])/([H_(2)CO_(3)]) = ` Antilog1.2921 = 19.59 `H_(2)CO_(3)` present in 10 ML of blood `(2 M H_(2)CO_(3))=(2)/(1000)xx10=0.02` mole `:. NaHCO_(3)` that should be present `=19.59xx0.02 = 0.3918 ` mole Volume of 5 M `NaHCO_(3)` required `= (1000)/(5) XX 0.3918 = 78.36` ml